1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/capsicum.h> 48 #include <sys/eventhandler.h> 49 #include <sys/kernel.h> 50 #include <sys/ktr.h> 51 #include <sys/malloc.h> 52 #include <sys/lock.h> 53 #include <sys/mutex.h> 54 #include <sys/proc.h> 55 #include <sys/procdesc.h> 56 #include <sys/jail.h> 57 #include <sys/tty.h> 58 #include <sys/wait.h> 59 #include <sys/vmmeter.h> 60 #include <sys/vnode.h> 61 #include <sys/racct.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sbuf.h> 64 #include <sys/signalvar.h> 65 #include <sys/sched.h> 66 #include <sys/sx.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/syslog.h> 69 #include <sys/ptrace.h> 70 #include <sys/acct.h> /* for acct_process() function prototype */ 71 #include <sys/filedesc.h> 72 #include <sys/sdt.h> 73 #include <sys/shm.h> 74 #include <sys/sem.h> 75 #include <sys/sysent.h> 76 #include <sys/timers.h> 77 #include <sys/umtx.h> 78 #ifdef KTRACE 79 #include <sys/ktrace.h> 80 #endif 81 82 #include <security/audit/audit.h> 83 #include <security/mac/mac_framework.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/vm_param.h> 88 #include <vm/pmap.h> 89 #include <vm/vm_map.h> 90 #include <vm/vm_page.h> 91 #include <vm/uma.h> 92 93 #ifdef KDTRACE_HOOKS 94 #include <sys/dtrace_bsd.h> 95 dtrace_execexit_func_t dtrace_fasttrap_exit; 96 #endif 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE1(proc, , , exit, "int"); 100 101 struct proc * 102 proc_realparent(struct proc *child) 103 { 104 struct proc *p, *parent; 105 106 sx_assert(&proctree_lock, SX_LOCKED); 107 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) 108 return (child->p_pptr->p_pid == child->p_oppid ? 109 child->p_pptr : child->p_reaper); 110 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) { 111 /* Cannot use LIST_PREV(), since the list head is not known. */ 112 p = __containerof(p->p_orphan.le_prev, struct proc, 113 p_orphan.le_next); 114 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0, 115 ("missing P_ORPHAN %p", p)); 116 } 117 parent = __containerof(p->p_orphan.le_prev, struct proc, 118 p_orphans.lh_first); 119 return (parent); 120 } 121 122 void 123 reaper_abandon_children(struct proc *p, bool exiting) 124 { 125 struct proc *p1, *p2, *ptmp; 126 127 sx_assert(&proctree_lock, SX_LOCKED); 128 KASSERT(p != initproc, ("reaper_abandon_children for initproc")); 129 if ((p->p_treeflag & P_TREE_REAPER) == 0) 130 return; 131 p1 = p->p_reaper; 132 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) { 133 LIST_REMOVE(p2, p_reapsibling); 134 p2->p_reaper = p1; 135 p2->p_reapsubtree = p->p_reapsubtree; 136 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling); 137 if (exiting && p2->p_pptr == p) { 138 PROC_LOCK(p2); 139 proc_reparent(p2, p1, true); 140 PROC_UNLOCK(p2); 141 } 142 } 143 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty")); 144 p->p_treeflag &= ~P_TREE_REAPER; 145 } 146 147 static void 148 reaper_clear(struct proc *p) 149 { 150 struct proc *p1; 151 bool clear; 152 153 sx_assert(&proctree_lock, SX_LOCKED); 154 LIST_REMOVE(p, p_reapsibling); 155 if (p->p_reapsubtree == 1) 156 return; 157 clear = true; 158 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) { 159 if (p1->p_reapsubtree == p->p_reapsubtree) { 160 clear = false; 161 break; 162 } 163 } 164 if (clear) 165 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree); 166 } 167 168 void 169 proc_clear_orphan(struct proc *p) 170 { 171 struct proc *p1; 172 173 sx_assert(&proctree_lock, SA_XLOCKED); 174 if ((p->p_treeflag & P_TREE_ORPHANED) == 0) 175 return; 176 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) { 177 p1 = LIST_NEXT(p, p_orphan); 178 if (p1 != NULL) 179 p1->p_treeflag |= P_TREE_FIRST_ORPHAN; 180 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN; 181 } 182 LIST_REMOVE(p, p_orphan); 183 p->p_treeflag &= ~P_TREE_ORPHANED; 184 } 185 186 /* 187 * exit -- death of process. 188 */ 189 void 190 sys_sys_exit(struct thread *td, struct sys_exit_args *uap) 191 { 192 193 exit1(td, uap->rval, 0); 194 /* NOTREACHED */ 195 } 196 197 /* 198 * Exit: deallocate address space and other resources, change proc state to 199 * zombie, and unlink proc from allproc and parent's lists. Save exit status 200 * and rusage for wait(). Check for child processes and orphan them. 201 */ 202 void 203 exit1(struct thread *td, int rval, int signo) 204 { 205 struct proc *p, *nq, *q, *t; 206 struct thread *tdt; 207 ksiginfo_t *ksi, *ksi1; 208 int signal_parent; 209 210 mtx_assert(&Giant, MA_NOTOWNED); 211 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo)); 212 213 p = td->td_proc; 214 /* 215 * XXX in case we're rebooting we just let init die in order to 216 * work around an unsolved stack overflow seen very late during 217 * shutdown on sparc64 when the gmirror worker process exists. 218 * XXX what to do now that sparc64 is gone... remove if? 219 */ 220 if (p == initproc && rebooting == 0) { 221 printf("init died (signal %d, exit %d)\n", signo, rval); 222 panic("Going nowhere without my init!"); 223 } 224 225 /* 226 * Deref SU mp, since the thread does not return to userspace. 227 */ 228 td_softdep_cleanup(td); 229 230 /* 231 * MUST abort all other threads before proceeding past here. 232 */ 233 PROC_LOCK(p); 234 /* 235 * First check if some other thread or external request got 236 * here before us. If so, act appropriately: exit or suspend. 237 * We must ensure that stop requests are handled before we set 238 * P_WEXIT. 239 */ 240 thread_suspend_check(0); 241 while (p->p_flag & P_HADTHREADS) { 242 /* 243 * Kill off the other threads. This requires 244 * some co-operation from other parts of the kernel 245 * so it may not be instantaneous. With this state set 246 * any thread entering the kernel from userspace will 247 * thread_exit() in trap(). Any thread attempting to 248 * sleep will return immediately with EINTR or EWOULDBLOCK 249 * which will hopefully force them to back out to userland 250 * freeing resources as they go. Any thread attempting 251 * to return to userland will thread_exit() from userret(). 252 * thread_exit() will unsuspend us when the last of the 253 * other threads exits. 254 * If there is already a thread singler after resumption, 255 * calling thread_single will fail; in that case, we just 256 * re-check all suspension request, the thread should 257 * either be suspended there or exit. 258 */ 259 if (!thread_single(p, SINGLE_EXIT)) 260 /* 261 * All other activity in this process is now 262 * stopped. Threading support has been turned 263 * off. 264 */ 265 break; 266 /* 267 * Recheck for new stop or suspend requests which 268 * might appear while process lock was dropped in 269 * thread_single(). 270 */ 271 thread_suspend_check(0); 272 } 273 KASSERT(p->p_numthreads == 1, 274 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 275 racct_sub(p, RACCT_NTHR, 1); 276 277 /* Let event handler change exit status */ 278 p->p_xexit = rval; 279 p->p_xsig = signo; 280 281 /* 282 * Ignore any pending request to stop due to a stop signal. 283 * Once P_WEXIT is set, future requests will be ignored as 284 * well. 285 */ 286 p->p_flag &= ~P_STOPPED_SIG; 287 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 288 289 /* Note that we are exiting. */ 290 p->p_flag |= P_WEXIT; 291 292 /* 293 * Wait for any processes that have a hold on our vmspace to 294 * release their reference. 295 */ 296 while (p->p_lock > 0) 297 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 298 299 PROC_UNLOCK(p); 300 /* Drain the limit callout while we don't have the proc locked */ 301 callout_drain(&p->p_limco); 302 303 #ifdef AUDIT 304 /* 305 * The Sun BSM exit token contains two components: an exit status as 306 * passed to exit(), and a return value to indicate what sort of exit 307 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 308 * what the return value is. 309 */ 310 AUDIT_ARG_EXIT(rval, 0); 311 AUDIT_SYSCALL_EXIT(0, td); 312 #endif 313 314 /* Are we a task leader with peers? */ 315 if (p->p_peers != NULL && p == p->p_leader) { 316 mtx_lock(&ppeers_lock); 317 q = p->p_peers; 318 while (q != NULL) { 319 PROC_LOCK(q); 320 kern_psignal(q, SIGKILL); 321 PROC_UNLOCK(q); 322 q = q->p_peers; 323 } 324 while (p->p_peers != NULL) 325 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 326 mtx_unlock(&ppeers_lock); 327 } 328 329 itimers_exit(p); 330 331 if (p->p_sysent->sv_onexit != NULL) 332 p->p_sysent->sv_onexit(p); 333 334 /* 335 * Check if any loadable modules need anything done at process exit. 336 * E.g. SYSV IPC stuff. 337 * Event handler could change exit status. 338 * XXX what if one of these generates an error? 339 */ 340 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 341 342 /* 343 * If parent is waiting for us to exit or exec, 344 * P_PPWAIT is set; we will wakeup the parent below. 345 */ 346 PROC_LOCK(p); 347 stopprofclock(p); 348 p->p_ptevents = 0; 349 350 /* 351 * Stop the real interval timer. If the handler is currently 352 * executing, prevent it from rearming itself and let it finish. 353 */ 354 if (timevalisset(&p->p_realtimer.it_value) && 355 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 356 timevalclear(&p->p_realtimer.it_interval); 357 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 358 KASSERT(!timevalisset(&p->p_realtimer.it_value), 359 ("realtime timer is still armed")); 360 } 361 362 PROC_UNLOCK(p); 363 364 umtx_thread_exit(td); 365 seltdfini(td); 366 367 /* 368 * Reset any sigio structures pointing to us as a result of 369 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown(). 370 */ 371 funsetownlst(&p->p_sigiolst); 372 373 /* 374 * Close open files and release open-file table. 375 * This may block! 376 */ 377 pdescfree(td); 378 fdescfree(td); 379 380 /* 381 * If this thread tickled GEOM, we need to wait for the giggling to 382 * stop before we return to userland 383 */ 384 if (td->td_pflags & TDP_GEOM) 385 g_waitidle(); 386 387 /* 388 * Remove ourself from our leader's peer list and wake our leader. 389 */ 390 if (p->p_leader->p_peers != NULL) { 391 mtx_lock(&ppeers_lock); 392 if (p->p_leader->p_peers != NULL) { 393 q = p->p_leader; 394 while (q->p_peers != p) 395 q = q->p_peers; 396 q->p_peers = p->p_peers; 397 wakeup(p->p_leader); 398 } 399 mtx_unlock(&ppeers_lock); 400 } 401 402 vmspace_exit(td); 403 (void)acct_process(td); 404 405 #ifdef KTRACE 406 ktrprocexit(td); 407 #endif 408 /* 409 * Release reference to text vnode 410 */ 411 if (p->p_textvp != NULL) { 412 vrele(p->p_textvp); 413 p->p_textvp = NULL; 414 } 415 416 /* 417 * Release our limits structure. 418 */ 419 lim_free(p->p_limit); 420 p->p_limit = NULL; 421 422 tidhash_remove(td); 423 424 /* 425 * Call machine-dependent code to release any 426 * machine-dependent resources other than the address space. 427 * The address space is released by "vmspace_exitfree(p)" in 428 * vm_waitproc(). 429 */ 430 cpu_exit(td); 431 432 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 433 434 /* 435 * Remove from allproc. It still sits in the hash. 436 */ 437 sx_xlock(&allproc_lock); 438 LIST_REMOVE(p, p_list); 439 sx_xunlock(&allproc_lock); 440 441 sx_xlock(&proctree_lock); 442 PROC_LOCK(p); 443 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 444 PROC_UNLOCK(p); 445 446 /* 447 * killjobc() might drop and re-acquire proctree_lock to 448 * revoke control tty if exiting process was a session leader. 449 */ 450 killjobc(); 451 452 /* 453 * Reparent all children processes: 454 * - traced ones to the original parent (or init if we are that parent) 455 * - the rest to init 456 */ 457 q = LIST_FIRST(&p->p_children); 458 if (q != NULL) /* only need this if any child is S_ZOMB */ 459 wakeup(q->p_reaper); 460 for (; q != NULL; q = nq) { 461 nq = LIST_NEXT(q, p_sibling); 462 ksi = ksiginfo_alloc(TRUE); 463 PROC_LOCK(q); 464 q->p_sigparent = SIGCHLD; 465 466 if ((q->p_flag & P_TRACED) == 0) { 467 proc_reparent(q, q->p_reaper, true); 468 if (q->p_state == PRS_ZOMBIE) { 469 /* 470 * Inform reaper about the reparented 471 * zombie, since wait(2) has something 472 * new to report. Guarantee queueing 473 * of the SIGCHLD signal, similar to 474 * the _exit() behaviour, by providing 475 * our ksiginfo. Ksi is freed by the 476 * signal delivery. 477 */ 478 if (q->p_ksi == NULL) { 479 ksi1 = NULL; 480 } else { 481 ksiginfo_copy(q->p_ksi, ksi); 482 ksi->ksi_flags |= KSI_INS; 483 ksi1 = ksi; 484 ksi = NULL; 485 } 486 PROC_LOCK(q->p_reaper); 487 pksignal(q->p_reaper, SIGCHLD, ksi1); 488 PROC_UNLOCK(q->p_reaper); 489 } else if (q->p_pdeathsig > 0) { 490 /* 491 * The child asked to received a signal 492 * when we exit. 493 */ 494 kern_psignal(q, q->p_pdeathsig); 495 } 496 } else { 497 /* 498 * Traced processes are killed since their existence 499 * means someone is screwing up. 500 */ 501 t = proc_realparent(q); 502 if (t == p) { 503 proc_reparent(q, q->p_reaper, true); 504 } else { 505 PROC_LOCK(t); 506 proc_reparent(q, t, true); 507 PROC_UNLOCK(t); 508 } 509 /* 510 * Since q was found on our children list, the 511 * proc_reparent() call moved q to the orphan 512 * list due to present P_TRACED flag. Clear 513 * orphan link for q now while q is locked. 514 */ 515 proc_clear_orphan(q); 516 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 517 q->p_flag2 &= ~P2_PTRACE_FSTP; 518 q->p_ptevents = 0; 519 FOREACH_THREAD_IN_PROC(q, tdt) { 520 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 521 TDB_FSTP); 522 } 523 kern_psignal(q, SIGKILL); 524 } 525 PROC_UNLOCK(q); 526 if (ksi != NULL) 527 ksiginfo_free(ksi); 528 } 529 530 /* 531 * Also get rid of our orphans. 532 */ 533 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 534 PROC_LOCK(q); 535 KASSERT(q->p_oppid == p->p_pid, 536 ("orphan %p of %p has unexpected oppid %d", q, p, 537 q->p_oppid)); 538 q->p_oppid = q->p_reaper->p_pid; 539 540 /* 541 * If we are the real parent of this process 542 * but it has been reparented to a debugger, then 543 * check if it asked for a signal when we exit. 544 */ 545 if (q->p_pdeathsig > 0) 546 kern_psignal(q, q->p_pdeathsig); 547 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 548 q->p_pid); 549 proc_clear_orphan(q); 550 PROC_UNLOCK(q); 551 } 552 553 #ifdef KDTRACE_HOOKS 554 if (SDT_PROBES_ENABLED()) { 555 int reason = CLD_EXITED; 556 if (WCOREDUMP(signo)) 557 reason = CLD_DUMPED; 558 else if (WIFSIGNALED(signo)) 559 reason = CLD_KILLED; 560 SDT_PROBE1(proc, , , exit, reason); 561 } 562 #endif 563 564 /* Save exit status. */ 565 PROC_LOCK(p); 566 p->p_xthread = td; 567 568 if (p->p_sysent->sv_ontdexit != NULL) 569 p->p_sysent->sv_ontdexit(td); 570 571 #ifdef KDTRACE_HOOKS 572 /* 573 * Tell the DTrace fasttrap provider about the exit if it 574 * has declared an interest. 575 */ 576 if (dtrace_fasttrap_exit) 577 dtrace_fasttrap_exit(p); 578 #endif 579 580 /* 581 * Notify interested parties of our demise. 582 */ 583 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 584 585 /* 586 * If this is a process with a descriptor, we may not need to deliver 587 * a signal to the parent. proctree_lock is held over 588 * procdesc_exit() to serialize concurrent calls to close() and 589 * exit(). 590 */ 591 signal_parent = 0; 592 if (p->p_procdesc == NULL || procdesc_exit(p)) { 593 /* 594 * Notify parent that we're gone. If parent has the 595 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 596 * notify process 1 instead (and hope it will handle this 597 * situation). 598 */ 599 PROC_LOCK(p->p_pptr); 600 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 601 if (p->p_pptr->p_sigacts->ps_flag & 602 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 603 struct proc *pp; 604 605 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 606 pp = p->p_pptr; 607 PROC_UNLOCK(pp); 608 proc_reparent(p, p->p_reaper, true); 609 p->p_sigparent = SIGCHLD; 610 PROC_LOCK(p->p_pptr); 611 612 /* 613 * Notify parent, so in case he was wait(2)ing or 614 * executing waitpid(2) with our pid, he will 615 * continue. 616 */ 617 wakeup(pp); 618 } else 619 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 620 621 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 622 signal_parent = 1; 623 } else if (p->p_sigparent != 0) { 624 if (p->p_sigparent == SIGCHLD) { 625 signal_parent = 1; 626 } else { /* LINUX thread */ 627 signal_parent = 2; 628 } 629 } 630 } else 631 PROC_LOCK(p->p_pptr); 632 sx_xunlock(&proctree_lock); 633 634 if (signal_parent == 1) { 635 childproc_exited(p); 636 } else if (signal_parent == 2) { 637 kern_psignal(p->p_pptr, p->p_sigparent); 638 } 639 640 /* Tell the prison that we are gone. */ 641 prison_proc_free(p->p_ucred->cr_prison); 642 643 /* 644 * The state PRS_ZOMBIE prevents other proesses from sending 645 * signal to the process, to avoid memory leak, we free memory 646 * for signal queue at the time when the state is set. 647 */ 648 sigqueue_flush(&p->p_sigqueue); 649 sigqueue_flush(&td->td_sigqueue); 650 651 /* 652 * We have to wait until after acquiring all locks before 653 * changing p_state. We need to avoid all possible context 654 * switches (including ones from blocking on a mutex) while 655 * marked as a zombie. We also have to set the zombie state 656 * before we release the parent process' proc lock to avoid 657 * a lost wakeup. So, we first call wakeup, then we grab the 658 * sched lock, update the state, and release the parent process' 659 * proc lock. 660 */ 661 wakeup(p->p_pptr); 662 cv_broadcast(&p->p_pwait); 663 sched_exit(p->p_pptr, td); 664 PROC_SLOCK(p); 665 p->p_state = PRS_ZOMBIE; 666 PROC_UNLOCK(p->p_pptr); 667 668 /* 669 * Save our children's rusage information in our exit rusage. 670 */ 671 PROC_STATLOCK(p); 672 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 673 PROC_STATUNLOCK(p); 674 675 /* 676 * Make sure the scheduler takes this thread out of its tables etc. 677 * This will also release this thread's reference to the ucred. 678 * Other thread parts to release include pcb bits and such. 679 */ 680 thread_exit(); 681 } 682 683 #ifndef _SYS_SYSPROTO_H_ 684 struct abort2_args { 685 char *why; 686 int nargs; 687 void **args; 688 }; 689 #endif 690 691 int 692 sys_abort2(struct thread *td, struct abort2_args *uap) 693 { 694 struct proc *p = td->td_proc; 695 struct sbuf *sb; 696 void *uargs[16]; 697 int error, i, sig; 698 699 /* 700 * Do it right now so we can log either proper call of abort2(), or 701 * note, that invalid argument was passed. 512 is big enough to 702 * handle 16 arguments' descriptions with additional comments. 703 */ 704 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 705 sbuf_clear(sb); 706 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 707 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 708 /* 709 * Since we can't return from abort2(), send SIGKILL in cases, where 710 * abort2() was called improperly 711 */ 712 sig = SIGKILL; 713 /* Prevent from DoSes from user-space. */ 714 if (uap->nargs < 0 || uap->nargs > 16) 715 goto out; 716 if (uap->nargs > 0) { 717 if (uap->args == NULL) 718 goto out; 719 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 720 if (error != 0) 721 goto out; 722 } 723 /* 724 * Limit size of 'reason' string to 128. Will fit even when 725 * maximal number of arguments was chosen to be logged. 726 */ 727 if (uap->why != NULL) { 728 error = sbuf_copyin(sb, uap->why, 128); 729 if (error < 0) 730 goto out; 731 } else { 732 sbuf_printf(sb, "(null)"); 733 } 734 if (uap->nargs > 0) { 735 sbuf_printf(sb, "("); 736 for (i = 0;i < uap->nargs; i++) 737 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 738 sbuf_printf(sb, ")"); 739 } 740 /* 741 * Final stage: arguments were proper, string has been 742 * successfully copied from userspace, and copying pointers 743 * from user-space succeed. 744 */ 745 sig = SIGABRT; 746 out: 747 if (sig == SIGKILL) { 748 sbuf_trim(sb); 749 sbuf_printf(sb, " (Reason text inaccessible)"); 750 } 751 sbuf_cat(sb, "\n"); 752 sbuf_finish(sb); 753 log(LOG_INFO, "%s", sbuf_data(sb)); 754 sbuf_delete(sb); 755 exit1(td, 0, sig); 756 return (0); 757 } 758 759 #ifdef COMPAT_43 760 /* 761 * The dirty work is handled by kern_wait(). 762 */ 763 int 764 owait(struct thread *td, struct owait_args *uap __unused) 765 { 766 int error, status; 767 768 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 769 if (error == 0) 770 td->td_retval[1] = status; 771 return (error); 772 } 773 #endif /* COMPAT_43 */ 774 775 /* 776 * The dirty work is handled by kern_wait(). 777 */ 778 int 779 sys_wait4(struct thread *td, struct wait4_args *uap) 780 { 781 struct rusage ru, *rup; 782 int error, status; 783 784 if (uap->rusage != NULL) 785 rup = &ru; 786 else 787 rup = NULL; 788 error = kern_wait(td, uap->pid, &status, uap->options, rup); 789 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 790 error = copyout(&status, uap->status, sizeof(status)); 791 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 792 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 793 return (error); 794 } 795 796 int 797 sys_wait6(struct thread *td, struct wait6_args *uap) 798 { 799 struct __wrusage wru, *wrup; 800 siginfo_t si, *sip; 801 idtype_t idtype; 802 id_t id; 803 int error, status; 804 805 idtype = uap->idtype; 806 id = uap->id; 807 808 if (uap->wrusage != NULL) 809 wrup = &wru; 810 else 811 wrup = NULL; 812 813 if (uap->info != NULL) { 814 sip = &si; 815 bzero(sip, sizeof(*sip)); 816 } else 817 sip = NULL; 818 819 /* 820 * We expect all callers of wait6() to know about WEXITED and 821 * WTRAPPED. 822 */ 823 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 824 825 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 826 error = copyout(&status, uap->status, sizeof(status)); 827 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 828 error = copyout(&wru, uap->wrusage, sizeof(wru)); 829 if (uap->info != NULL && error == 0) 830 error = copyout(&si, uap->info, sizeof(si)); 831 return (error); 832 } 833 834 /* 835 * Reap the remains of a zombie process and optionally return status and 836 * rusage. Asserts and will release both the proctree_lock and the process 837 * lock as part of its work. 838 */ 839 void 840 proc_reap(struct thread *td, struct proc *p, int *status, int options) 841 { 842 struct proc *q, *t; 843 844 sx_assert(&proctree_lock, SA_XLOCKED); 845 PROC_LOCK_ASSERT(p, MA_OWNED); 846 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 847 848 mtx_spin_wait_unlocked(&p->p_slock); 849 850 q = td->td_proc; 851 852 if (status) 853 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 854 if (options & WNOWAIT) { 855 /* 856 * Only poll, returning the status. Caller does not wish to 857 * release the proc struct just yet. 858 */ 859 PROC_UNLOCK(p); 860 sx_xunlock(&proctree_lock); 861 return; 862 } 863 864 PROC_LOCK(q); 865 sigqueue_take(p->p_ksi); 866 PROC_UNLOCK(q); 867 868 /* 869 * If we got the child via a ptrace 'attach', we need to give it back 870 * to the old parent. 871 */ 872 if (p->p_oppid != p->p_pptr->p_pid) { 873 PROC_UNLOCK(p); 874 t = proc_realparent(p); 875 PROC_LOCK(t); 876 PROC_LOCK(p); 877 CTR2(KTR_PTRACE, 878 "wait: traced child %d moved back to parent %d", p->p_pid, 879 t->p_pid); 880 proc_reparent(p, t, false); 881 PROC_UNLOCK(p); 882 pksignal(t, SIGCHLD, p->p_ksi); 883 wakeup(t); 884 cv_broadcast(&p->p_pwait); 885 PROC_UNLOCK(t); 886 sx_xunlock(&proctree_lock); 887 return; 888 } 889 PROC_UNLOCK(p); 890 891 /* 892 * Remove other references to this process to ensure we have an 893 * exclusive reference. 894 */ 895 sx_xlock(PIDHASHLOCK(p->p_pid)); 896 LIST_REMOVE(p, p_hash); 897 sx_xunlock(PIDHASHLOCK(p->p_pid)); 898 LIST_REMOVE(p, p_sibling); 899 reaper_abandon_children(p, true); 900 reaper_clear(p); 901 PROC_LOCK(p); 902 proc_clear_orphan(p); 903 PROC_UNLOCK(p); 904 leavepgrp(p); 905 if (p->p_procdesc != NULL) 906 procdesc_reap(p); 907 sx_xunlock(&proctree_lock); 908 909 proc_id_clear(PROC_ID_PID, p->p_pid); 910 911 PROC_LOCK(p); 912 knlist_detach(p->p_klist); 913 p->p_klist = NULL; 914 PROC_UNLOCK(p); 915 916 /* 917 * Removal from allproc list and process group list paired with 918 * PROC_LOCK which was executed during that time should guarantee 919 * nothing can reach this process anymore. As such further locking 920 * is unnecessary. 921 */ 922 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 923 924 PROC_LOCK(q); 925 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 926 PROC_UNLOCK(q); 927 928 /* 929 * Decrement the count of procs running with this uid. 930 */ 931 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 932 933 /* 934 * Destroy resource accounting information associated with the process. 935 */ 936 #ifdef RACCT 937 if (racct_enable) { 938 PROC_LOCK(p); 939 racct_sub(p, RACCT_NPROC, 1); 940 PROC_UNLOCK(p); 941 } 942 #endif 943 racct_proc_exit(p); 944 945 /* 946 * Free credentials, arguments, and sigacts. 947 */ 948 proc_unset_cred(p); 949 pargs_drop(p->p_args); 950 p->p_args = NULL; 951 sigacts_free(p->p_sigacts); 952 p->p_sigacts = NULL; 953 954 /* 955 * Do any thread-system specific cleanups. 956 */ 957 thread_wait(p); 958 959 /* 960 * Give vm and machine-dependent layer a chance to free anything that 961 * cpu_exit couldn't release while still running in process context. 962 */ 963 vm_waitproc(p); 964 #ifdef MAC 965 mac_proc_destroy(p); 966 #endif 967 968 KASSERT(FIRST_THREAD_IN_PROC(p), 969 ("proc_reap: no residual thread!")); 970 uma_zfree(proc_zone, p); 971 atomic_add_int(&nprocs, -1); 972 } 973 974 static int 975 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 976 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 977 int check_only) 978 { 979 struct rusage *rup; 980 981 sx_assert(&proctree_lock, SA_XLOCKED); 982 983 PROC_LOCK(p); 984 985 switch (idtype) { 986 case P_ALL: 987 if (p->p_procdesc == NULL || 988 (p->p_pptr == td->td_proc && 989 (p->p_flag & P_TRACED) != 0)) { 990 break; 991 } 992 993 PROC_UNLOCK(p); 994 return (0); 995 case P_PID: 996 if (p->p_pid != (pid_t)id) { 997 PROC_UNLOCK(p); 998 return (0); 999 } 1000 break; 1001 case P_PGID: 1002 if (p->p_pgid != (pid_t)id) { 1003 PROC_UNLOCK(p); 1004 return (0); 1005 } 1006 break; 1007 case P_SID: 1008 if (p->p_session->s_sid != (pid_t)id) { 1009 PROC_UNLOCK(p); 1010 return (0); 1011 } 1012 break; 1013 case P_UID: 1014 if (p->p_ucred->cr_uid != (uid_t)id) { 1015 PROC_UNLOCK(p); 1016 return (0); 1017 } 1018 break; 1019 case P_GID: 1020 if (p->p_ucred->cr_gid != (gid_t)id) { 1021 PROC_UNLOCK(p); 1022 return (0); 1023 } 1024 break; 1025 case P_JAILID: 1026 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1027 PROC_UNLOCK(p); 1028 return (0); 1029 } 1030 break; 1031 /* 1032 * It seems that the thread structures get zeroed out 1033 * at process exit. This makes it impossible to 1034 * support P_SETID, P_CID or P_CPUID. 1035 */ 1036 default: 1037 PROC_UNLOCK(p); 1038 return (0); 1039 } 1040 1041 if (p_canwait(td, p)) { 1042 PROC_UNLOCK(p); 1043 return (0); 1044 } 1045 1046 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1047 PROC_UNLOCK(p); 1048 return (0); 1049 } 1050 1051 /* 1052 * This special case handles a kthread spawned by linux_clone 1053 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1054 * functions need to be able to distinguish between waiting 1055 * on a process and waiting on a thread. It is a thread if 1056 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1057 * signifies we want to wait for threads and not processes. 1058 */ 1059 if ((p->p_sigparent != SIGCHLD) ^ 1060 ((options & WLINUXCLONE) != 0)) { 1061 PROC_UNLOCK(p); 1062 return (0); 1063 } 1064 1065 if (siginfo != NULL) { 1066 bzero(siginfo, sizeof(*siginfo)); 1067 siginfo->si_errno = 0; 1068 1069 /* 1070 * SUSv4 requires that the si_signo value is always 1071 * SIGCHLD. Obey it despite the rfork(2) interface 1072 * allows to request other signal for child exit 1073 * notification. 1074 */ 1075 siginfo->si_signo = SIGCHLD; 1076 1077 /* 1078 * This is still a rough estimate. We will fix the 1079 * cases TRAPPED, STOPPED, and CONTINUED later. 1080 */ 1081 if (WCOREDUMP(p->p_xsig)) { 1082 siginfo->si_code = CLD_DUMPED; 1083 siginfo->si_status = WTERMSIG(p->p_xsig); 1084 } else if (WIFSIGNALED(p->p_xsig)) { 1085 siginfo->si_code = CLD_KILLED; 1086 siginfo->si_status = WTERMSIG(p->p_xsig); 1087 } else { 1088 siginfo->si_code = CLD_EXITED; 1089 siginfo->si_status = p->p_xexit; 1090 } 1091 1092 siginfo->si_pid = p->p_pid; 1093 siginfo->si_uid = p->p_ucred->cr_uid; 1094 1095 /* 1096 * The si_addr field would be useful additional 1097 * detail, but apparently the PC value may be lost 1098 * when we reach this point. bzero() above sets 1099 * siginfo->si_addr to NULL. 1100 */ 1101 } 1102 1103 /* 1104 * There should be no reason to limit resources usage info to 1105 * exited processes only. A snapshot about any resources used 1106 * by a stopped process may be exactly what is needed. 1107 */ 1108 if (wrusage != NULL) { 1109 rup = &wrusage->wru_self; 1110 *rup = p->p_ru; 1111 PROC_STATLOCK(p); 1112 calcru(p, &rup->ru_utime, &rup->ru_stime); 1113 PROC_STATUNLOCK(p); 1114 1115 rup = &wrusage->wru_children; 1116 *rup = p->p_stats->p_cru; 1117 calccru(p, &rup->ru_utime, &rup->ru_stime); 1118 } 1119 1120 if (p->p_state == PRS_ZOMBIE && !check_only) { 1121 proc_reap(td, p, status, options); 1122 return (-1); 1123 } 1124 return (1); 1125 } 1126 1127 int 1128 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1129 struct rusage *rusage) 1130 { 1131 struct __wrusage wru, *wrup; 1132 idtype_t idtype; 1133 id_t id; 1134 int ret; 1135 1136 /* 1137 * Translate the special pid values into the (idtype, pid) 1138 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1139 * kern_wait6() on its own. 1140 */ 1141 if (pid == WAIT_ANY) { 1142 idtype = P_ALL; 1143 id = 0; 1144 } else if (pid < 0) { 1145 idtype = P_PGID; 1146 id = (id_t)-pid; 1147 } else { 1148 idtype = P_PID; 1149 id = (id_t)pid; 1150 } 1151 1152 if (rusage != NULL) 1153 wrup = &wru; 1154 else 1155 wrup = NULL; 1156 1157 /* 1158 * For backward compatibility we implicitly add flags WEXITED 1159 * and WTRAPPED here. 1160 */ 1161 options |= WEXITED | WTRAPPED; 1162 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1163 if (rusage != NULL) 1164 *rusage = wru.wru_self; 1165 return (ret); 1166 } 1167 1168 static void 1169 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1170 int *status, int options, int si_code) 1171 { 1172 bool cont; 1173 1174 PROC_LOCK_ASSERT(p, MA_OWNED); 1175 sx_assert(&proctree_lock, SA_XLOCKED); 1176 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1177 si_code == CLD_CONTINUED); 1178 1179 cont = si_code == CLD_CONTINUED; 1180 if ((options & WNOWAIT) == 0) { 1181 if (cont) 1182 p->p_flag &= ~P_CONTINUED; 1183 else 1184 p->p_flag |= P_WAITED; 1185 PROC_LOCK(td->td_proc); 1186 sigqueue_take(p->p_ksi); 1187 PROC_UNLOCK(td->td_proc); 1188 } 1189 sx_xunlock(&proctree_lock); 1190 if (siginfo != NULL) { 1191 siginfo->si_code = si_code; 1192 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1193 } 1194 if (status != NULL) 1195 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1196 PROC_UNLOCK(p); 1197 td->td_retval[0] = p->p_pid; 1198 } 1199 1200 int 1201 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1202 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1203 { 1204 struct proc *p, *q; 1205 pid_t pid; 1206 int error, nfound, ret; 1207 bool report; 1208 1209 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1210 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1211 AUDIT_ARG_VALUE(options); 1212 1213 q = td->td_proc; 1214 1215 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1216 PROC_LOCK(q); 1217 id = (id_t)q->p_pgid; 1218 PROC_UNLOCK(q); 1219 idtype = P_PGID; 1220 } 1221 1222 /* If we don't know the option, just return. */ 1223 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1224 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1225 return (EINVAL); 1226 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1227 /* 1228 * We will be unable to find any matching processes, 1229 * because there are no known events to look for. 1230 * Prefer to return error instead of blocking 1231 * indefinitely. 1232 */ 1233 return (EINVAL); 1234 } 1235 1236 loop: 1237 if (q->p_flag & P_STATCHILD) { 1238 PROC_LOCK(q); 1239 q->p_flag &= ~P_STATCHILD; 1240 PROC_UNLOCK(q); 1241 } 1242 sx_xlock(&proctree_lock); 1243 loop_locked: 1244 nfound = 0; 1245 LIST_FOREACH(p, &q->p_children, p_sibling) { 1246 pid = p->p_pid; 1247 ret = proc_to_reap(td, p, idtype, id, status, options, 1248 wrusage, siginfo, 0); 1249 if (ret == 0) 1250 continue; 1251 else if (ret != 1) { 1252 td->td_retval[0] = pid; 1253 return (0); 1254 } 1255 1256 nfound++; 1257 PROC_LOCK_ASSERT(p, MA_OWNED); 1258 1259 if ((options & WTRAPPED) != 0 && 1260 (p->p_flag & P_TRACED) != 0) { 1261 PROC_SLOCK(p); 1262 report = 1263 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1264 p->p_suspcount == p->p_numthreads && 1265 (p->p_flag & P_WAITED) == 0); 1266 PROC_SUNLOCK(p); 1267 if (report) { 1268 CTR4(KTR_PTRACE, 1269 "wait: returning trapped pid %d status %#x " 1270 "(xstat %d) xthread %d", 1271 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1272 p->p_xthread != NULL ? 1273 p->p_xthread->td_tid : -1); 1274 report_alive_proc(td, p, siginfo, status, 1275 options, CLD_TRAPPED); 1276 return (0); 1277 } 1278 } 1279 if ((options & WUNTRACED) != 0 && 1280 (p->p_flag & P_STOPPED_SIG) != 0) { 1281 PROC_SLOCK(p); 1282 report = (p->p_suspcount == p->p_numthreads && 1283 ((p->p_flag & P_WAITED) == 0)); 1284 PROC_SUNLOCK(p); 1285 if (report) { 1286 report_alive_proc(td, p, siginfo, status, 1287 options, CLD_STOPPED); 1288 return (0); 1289 } 1290 } 1291 if ((options & WCONTINUED) != 0 && 1292 (p->p_flag & P_CONTINUED) != 0) { 1293 report_alive_proc(td, p, siginfo, status, options, 1294 CLD_CONTINUED); 1295 return (0); 1296 } 1297 PROC_UNLOCK(p); 1298 } 1299 1300 /* 1301 * Look in the orphans list too, to allow the parent to 1302 * collect it's child exit status even if child is being 1303 * debugged. 1304 * 1305 * Debugger detaches from the parent upon successful 1306 * switch-over from parent to child. At this point due to 1307 * re-parenting the parent loses the child to debugger and a 1308 * wait4(2) call would report that it has no children to wait 1309 * for. By maintaining a list of orphans we allow the parent 1310 * to successfully wait until the child becomes a zombie. 1311 */ 1312 if (nfound == 0) { 1313 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1314 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1315 NULL, NULL, 1); 1316 if (ret != 0) { 1317 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1318 (int)td->td_retval[0])); 1319 PROC_UNLOCK(p); 1320 nfound++; 1321 break; 1322 } 1323 } 1324 } 1325 if (nfound == 0) { 1326 sx_xunlock(&proctree_lock); 1327 return (ECHILD); 1328 } 1329 if (options & WNOHANG) { 1330 sx_xunlock(&proctree_lock); 1331 td->td_retval[0] = 0; 1332 return (0); 1333 } 1334 PROC_LOCK(q); 1335 if (q->p_flag & P_STATCHILD) { 1336 q->p_flag &= ~P_STATCHILD; 1337 PROC_UNLOCK(q); 1338 goto loop_locked; 1339 } 1340 sx_xunlock(&proctree_lock); 1341 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1342 if (error) 1343 return (error); 1344 goto loop; 1345 } 1346 1347 void 1348 proc_add_orphan(struct proc *child, struct proc *parent) 1349 { 1350 1351 sx_assert(&proctree_lock, SX_XLOCKED); 1352 KASSERT((child->p_flag & P_TRACED) != 0, 1353 ("proc_add_orphan: not traced")); 1354 1355 if (LIST_EMPTY(&parent->p_orphans)) { 1356 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1357 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1358 } else { 1359 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1360 child, p_orphan); 1361 } 1362 child->p_treeflag |= P_TREE_ORPHANED; 1363 } 1364 1365 /* 1366 * Make process 'parent' the new parent of process 'child'. 1367 * Must be called with an exclusive hold of proctree lock. 1368 */ 1369 void 1370 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1371 { 1372 1373 sx_assert(&proctree_lock, SX_XLOCKED); 1374 PROC_LOCK_ASSERT(child, MA_OWNED); 1375 if (child->p_pptr == parent) 1376 return; 1377 1378 PROC_LOCK(child->p_pptr); 1379 sigqueue_take(child->p_ksi); 1380 PROC_UNLOCK(child->p_pptr); 1381 LIST_REMOVE(child, p_sibling); 1382 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1383 1384 proc_clear_orphan(child); 1385 if ((child->p_flag & P_TRACED) != 0) { 1386 proc_add_orphan(child, child->p_pptr); 1387 } 1388 1389 child->p_pptr = parent; 1390 if (set_oppid) 1391 child->p_oppid = parent->p_pid; 1392 } 1393